The present invention relates to the field of operating devices inserted inside casings of hydrocarbon wells. In particular, the invention relates to a method and system for position and orientation of a device relative to a well.
After hydrocarbon wells are drilled a completion process includes the placement of a metal casing (often made of steel) inside the borehole. Devices can then be lowered into the well inside of the casing. Some devices have a function that is dependent on the radial angle that the device faces when the function is performed. For example, a perforating gun is a device that can be lowered into a casing to perforate the casing (as well as the cement holding the casing in place and the surrounding formation). In some circumstances, perforations in a particular direction are advantageous. One circumstance would be in hydraulic fractured wells where injection pressures can be reduced and flow rates increased if the perforating holes are aligned with the direction of principal maximum stress. Another circumstance would be in wells that include sensors and communication lines where perforations in a particular direction could damage the other equipment. A second example device would be a sensor that receives information dependent on the angle that it is facing. Being able to determine the facing angle of the device assists the well operator in deciding whether the device should be activated.